Stationary Power for Micro-Storage

posted Jan 17, 2013, 5:40 PM by Steven Harbauer

It's a little ironic that energy storage seems new when in fact it's decades old. It all comes from when a power failure can potentially cause enough damage or possibly create a danger to life then the "payback" is fairly quick. When disk drives were washing machines and a power failure would cause one to be seriously damaged, not only did you lose the device but the information stored on the device. That was just too painful so the "UPS" industry was born. Still, there are plenty of people that think people in brown uniforms driving brown trucks whenever the term "UPS" is used. So Mission Critical Power Systems, Stationary Power Systems, Emergency or Stored Energy Power Systems were terms or phrases coined to somehow differentiate it from an actual "generator."

Now what's more amazing is the use of electric vehicle or "motive" power systems being anchored to the concrete pad and called "stationary power." This equipment is not designed to work in a 24/7 environment that is typical of a UPS or Stationary power system. The other thing is vehicle systems are NOT intended to carry the building load. So we are seeing already some interesting effects and even failures. For sure, we don't our brand-new, special Energy 3.0 "micro-grid" taken down or in "bypass" because the vehicle charger found itself picking the entire load of the building.

Stationary power has gradually seen the integration of battery monitoring systems. The purpose of the monitor is to watch every battery. Each battery regardless of chemistry is like a "little person" and unique from the assembly. Oh sure, there are similarities and you can get a pretty good run of extremely similar units. But the minute you cycle power, and discharge the batteries, each one is now on it's own. So as you charge the battery it's now a process control problem. Cycling batteries is a lot like "herding house cats." Each one needs it's own charger in fact.

So what the electric vehicle industry has come to realize it needs "balance" the charging of the batteries. All kinds of schemes have been developed in addition to different charging algorithms. So it's really the "wild west" in the power conversion market. It's undefined, plagued with several different communication interfaces and protocols. While many companies and organizations claim to have "nailed it," I don't think there is really a single "gets it all at once" solution. For sure, you can't just buy a Battery Management System that is universal to any chemistry from the local wholesaler.

Which comes down to predicting available charge or capacity. It's still art as well as science.